ST. LOUIS, MO(St. Louis Public Radio) -
The first major test of national health care overhaul legislation was voted on by Missourians on Tuesday.

The core of Proposition C is an opt-out provision that bars the government from forcing Missourians to buy individual health insurance, as part of the administration's larger overhaul of health care.

The measure's passage was good news for Republicans who oppose the President's agenda on health care.

State Senator Jane Cunningham was the measure's lead sponsor. She says Prop C sends a clear message to Washington about the individual mandate.

"It is unprecedented in the United States of America for a government to say, you will buy a product, with your own money against your will,'" says Cunningham. "That has never before happened in America. And that question needs to be addressed to the U.S. Supreme Court."

Cunningham predicts that Missouri is just the first domino in what will become a groundswell of state opposition to President Obama's health care agenda.

Opponents of the ballot measure say Prop C's intent is purely political and regardless of the vote, federal law trumps state law on issues such as these

Amy Smoucha is a health care organizer with Missouri Jobs With Justice.

"I wouldn't over estimate the significance of a measure like Proposition C," says Smoucha. "It's a low turnout election. It was highly politicized and a very narrow question. I think this is one of those political tricks that will fade away into history and folks won't remember it for very long."

Smoucha says other key provisions of the health care overhaul, such as not denying coverage based on pre-existing conditions, or allowing young adults to remain on their parent's coverage are still set to go into effect later this year.